Heidi Goodrich-Blair
Email:
hgblair @bact.wisc.eduAssociate Professor
Degrees
Ph.D., 1993, University of Albany, SUNY
Postdoctoral Research
University at Albany, SUNY; Harvard Medical School
Lab Members
MUTUALISM AND PATHOGENESIS: MOLECULAR MECHANISMS OF NEMATODE/BACTERIUM/INSECT INTERACTIONSOur research is aimed at understanding, at a molecular level, how microbes survive and flourish in the environments they occupy. Survival for many microbes is dependent upon their ability to interact with other organisms. To understand host-microbe interactions, our lab focuses on a gamma-proteobacterium, Xenorhabdus nematophila. This bacterium is a symbiont of the insect-infecting nematode Steinernema carpocapsae and is responsible for killing the insect larvae that this pair infects.
X. nematophila resides as a symbiont within a specialized intestinal vesicle of the insect-infecting nematode. Each of these two organisms requires the other to grow and reproduce, a process that occurs within the insect. The bacterium, X. nematophila, is the actual insect pathogen; it produces exo- and endo-toxins that can rapidly kill an insect host. In addition, once inside an insect host, X. nematophila expresses degradative functions such as proteases and lipases that convert insect host tissues into products that can be utilized by the nematode. Thus, X. nematophila is essential for both insect host killing and nematode development.
X. nematophila is a model for both positive and negative host-microbe interactions, knowledge of which will improve our ability to combat and/or utilize microorganisms to our own benefit. Furthermore, X. nematophila is part of a tripartite system (insect, nematode, and bacterium) that has potential use as an alternative to insecticides. Understanding the relationship between the members of this system will greatly improve their use in biocontrol. In our work we use molecular, genetic, and biochemical techniques to ask basic biological questions involving the interaction of X. nematophila with its hosts, examining the interaction from both the bacterium and host sides.
The results of our work will have an impact on our understanding of any system in which microbes interact with a eukaryotic host, including pathogenic and symbiotic associations. It will illustrate the mechanisms by which a single bacterium can form a beneficial association with one organism and a harmful interaction with another. In addition, our findings will have implications in the fields of biocontrol and microbial ecology and development.
References (past five years):
Richards, G.R., Herbert, E.E., Park, Y. and Goodrich-Blair, H. (2008). Xenorhabdus nematophila lrhA is necessary for motility, flagellar export, lipase activity and virulence toward Manduca sexta insects. J. Bacteriol. 190: 4870-4879.
Cowles, C.E. and Goodrich-Blair, H. (2008) The Xenorhabdus nematophila nilABC genes confer the ability of Xenorhabdus spp. to colonize Steinernema carpocapase nematodes. J. Bacteriol. 190: 4121–4128.
Stock, S.P. and Goodrich-Blair, H. (2008) Entomopathogenic nematodes and their bacterial symbionts: The inside out of a mutualistic association. Symbiosis. 46:65-76.
Herbert, E.E., Cowles, K.N. and Goodrich-Blair, H. (2007) CpxRA regulates mutualism and pathogenesis in Xenorhabdus nematophila. Appl. Env. Microbiol. 73:7826-7836.
Latreille, P., Norton, S., Slater, S., Miller, N., Barbazuk, B., Bode, H., Darby, C., Du, Zijin, Forst, S., Gaudriault, S., Goodner, B., Goodrich-Blair, H., and Goldman, B.S. (2007) Optical mapping as a routine tool in bacterial genome sequencing. BMC Genomics 8:321.
Herbert, E.E. and Goodrich-Blair, H. (2007) Friend and foe: The two faces of Xenorhabdus nematophila. Nat. Rev. Microbiol. 5:634-646.
Goodrich-Blair, H. (2007) They've got a ticket to ride: Xenorhabdus nematophila-Steinernema carpocapsae symbiosis. Curr. Op. Microbiol. 10:225-230.
Flores-Lara, Y., Renneckar, D., Forst, S., Goodrich-Blair, H., and Stock, P. (2007) Influence of nematode age and culture conditions on morphological and physiological parameters in the vesicle of Steinernema carpocapsae J. Inv. Pathol. 95:110-118.
Goodrich-Blair, H., and Clarke, D.J. (2007) Mutualism and pathogenesis in Xenorhabdus and Photorhabdus: two roads to the same destination. Mol. Microbiol. 64: 260-268.
Cowles, K.N., Cowles, C.E., Martens, E.C., and Goodrich-Blair, H. (2007) The global regulator Lrp contributes to both beneficial and pathogenic microbe-host interactions in Xenorhabdus nematophila. Cellular Microbiol. 9:1311-1323.
Park, Y. Herbert, E.E., Cowles, C.E., Cowles, K.N., Menard, M.L., Orchard, S.S., and Goodrich-Blair, H. (2007) Clonal variation in Xenorhabdus nematophila virulence and suppression of Manduca sexta immunity. Cellular Microbiol. 9:645-656.
Cowles, C.E. and Goodrich-Blair, H. (2006) nilR is necessary for coordinate repression of Xenorhabdus nematophila mutualism genes. Molec. Microbiol. 62:760-771.
Martens, E.C. and Goodrich-Blair, H. (2005) The Steinernema carpocapsae intestinal vesicle contains a sub-cellular structure with which Xenorhabdus nematophila associates during colonization initiation. Cellular Microbiol. 7:1723-1735.
Orchard, S.S. and Goodrich-Blair, H. (2005) An encoded N-terminal extension results in low levels of heterologous protein expression in Escherichia coli. Microbial Cell Factories. 4:22.
Martens, E.C., Russell, F.M., and Goodrich-Blair, H. (2005) Analysis of Xenorhabdus nematophila metabolic mutants yields insight into stages of Steinernema carpocapsae nematode intestinal colonization. Molec. Microbiol. 51:28-45.
Orchard, S.S. and Goodrich-Blair, H. (2005) Pyrimidine salvage confers a competitive advantage in Xenorhabdus nematophila nematode colonization. Appl. Env. Microbiol. 71:6254-6259.
Cowles, K.N. and Goodrich-Blair, H. (2005) Activity and expression of the Xenorhabdus nematophila haemolysin encoded by the xhlBA locus. Cellular Microbiol. 7:209-219.
Cowles, C.E., and Goodrich-Blair, H. (2004) Characterization of a lipoprotein, NilC, required by Xenorhabdus nematophila for mutualism with its nematode host. Molec. Microbiol. 54:464-477.
Orchard, S.O., and Goodrich-Blair, H. (2004) Identification and functional characterization of a Xenorhabdus nematophila oligopeptide permease. Appl. Env. Microbiol. 70:5621-5627.
Mitani, D.K., Kaya, H.K., and Goodrich-Blair, H. (2004) Comparative study of the entomopathogenic nematode, Steinernema carpocapsae, reared on mutant and wild-type Xenorhabdus nematophila. Biological Control. 29:382-391.
Relevant links
Symbiosis at UW-Madison: http://www.cals.wisc.edu/Symbiosis
Xenorhabdus genome sequencing project: http://xenorhabdus.danforthcenter.org
Entomopathogenic nematodes and bacteria:
As a teaching tool: http://www.bact.wisc.edu/epnb/SecretLives.htm
http://www.bact.wisc.edu/epnb/
http://www2.oardc.ohio-state.edu/nematodes/
Animal-microbe associations:
